Hemoglobin Test Test
A hemoglobin test measures the amount of hemoglobin in your blood. Hemoglobin is a protein in red blood cells that carries oxygen from your lungs to the rest of your body. This test is often used to check for anemia, a condition where your body doesn't have enough healthy red blood cells.
What this test measures
A hemoglobin test measures the levels of hemoglobin in your blood. Hemoglobin is an iron-rich protein in your red blood cells that carries oxygen from your lungs to the rest of your body.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
High hemoglobin levels may be a sign of lung disease, heart disease, polycythemia vera, or sleep apnea. Living at a high altitude can also cause high levels.
Lower-than-normal results
Low hemoglobin levels may be a sign of different types of anemia, thalassemia, iron deficiency, liver disease, cancer, blood loss, or lack of certain nutrients like iron or vitamin B-12.
Frequently asked questions
What is a hemoglobin test?
A hemoglobin test measures the levels of hemoglobin in your blood. Hemoglobin is a protein in red blood cells that carries oxygen.
Why is a hemoglobin test done?
It is often used to check for anemia, a condition where your body doesn't make enough healthy red blood cells.
Is a hemoglobin test the same as an A1C test?
No. A hemoglobin test is different from a hemoglobin A1C test, which checks your average blood sugar.
What can cause low hemoglobin levels?
Low levels may be caused by anemia, iron deficiency, liver disease, cancer, blood loss, or lack of certain nutrients.
What can cause high hemoglobin levels?
High levels may be caused by lung disease, heart disease, polycythemia vera, sleep apnea, or living at a high altitude.
Related lab tests
Sources
- MedlinePlus: Hemoglobin Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.